This invention relates to an apparatus and method for the smoking of food. More particularly, this invention relates to a smoker that is capable of smoking food either under pressure or in a partial vacuum.
For many years it has been found advantageous to smoke meats and other foods to preserve the foods and to impart a smoke flavor to the foods to enhance the flavor of the foods. Demand for smoked foods, particularly meats, has been great for many years and continues to be great. Therefore, there has been a continual need for a device that facilitates the smoking of such foods and that performs the smoking in an efficient and satisfactory manner.
Historically, foods, particularly meats, have been smoked at atmospheric pressures over long periods of time. Such smoking also served to cook the meat while imparting the smoke flavor. It was later found that the time required to adequately smoke and cook the meats could be reduced if the smoking and cooking processes could be performed in combination and under pressure. It was also found that smoking and cooking meat under pressure imparted more smoke flavor to the meat, tended to cause the meat to retain additional moisture, and caused the meat to be more tender as compared to meat smoked at atmospheric pressure.
In addition to smoking foods under pressure, it has been found that smoking and cooking foods at a pressure less than the surrounding atmospheric pressure draws moisture from the foods and helps to more quickly preserve the foods. For example, meat jerky smoked at less than atmospheric pressure cures more quickly and with a more desirable texture than does meat jerky smoked at atmospheric pressure. Heretofore, no devices have provided for the smoking of foods at a pressure less than atmospheric pressure.
Prior devices have performed the smoking and cooking processes simultaneously and under pressure with some success. U.S. Pat. No. 4,130,052 to Jacobson disclosed a pressurizable smoking enclosure which contained a combination smoke producing and heating element. Meat or other foods were placed within the enclosure and the enclosure was sealed to become airtight. Then, wood blocks or chips were placed upon the heating element and the heating element was then activated. Resultantly, the element heated the enclosure, caused the pressure within the enclosure to increase, and caused the wood contacting the element to smoke. Smoke filled the vessel thereby permeating the food contained within the enclosure and cooking the food contained within the enclosure. The Jacobson device, however, had a major shortcoming. The temperature within the enclosure, the pressure within the enclosure, and the smoke concentration within the enclosure all depended upon the thermal output of the heating element. Resultantly, only one of the three parameters within the enclosure could be controlled at any given time by controlling the heating element. The other two parameters therefore were not simultaneously controllable. Because of this, the cooking environment within the enclosure could not be satisfactorily controlled.
U.S. Pat. No. 4,469,020 to Hamilton et al. disclosed a pressure smoker and cooker which overcame some limitations of the Jacobson device. The Hamilton et al. device included separate control of the temperature, pressure, and smoke concentration within the enclosure. A smoke generator external to the enclosure created smoke that was then pumped into the enclosure thereby filling the enclosure with smoke and pressurizing the enclosure. A pressure relief valve was employed to control the pressure within the enclosure and a flame was then ignited within a heat tube that passed through the pressurized enclosure. The flame could be controlled to regulate the temperature within the enclosure without varying the smoke concentration within the enclosure. Thus, the Hamilton et al. device allowed for separate control of the temperature, pressure, and smoke concentration within the enclosure.
Even though the Hamilton et al. device provided for separate controls, it suffered a shortcoming in its smoke delivery system. A first smoke delivery system described in Hamilton et al. (FIG. 2) required that a compressor receive smoke filled air from a fire box, compress the smoke filled air, and deliver it to the enclosure. Over a relatively short period of time, the particles in the smoke filled air contaminated the compressor and caused the compressor to fail. A second smoke delivery system (FIG. 4) required that the smoke be filtered prior to its passage through the compressor. This system partially protected the compressor, but it also removed the smoke from the air before it was delivered to the enclosure thereby defeating the function of the smoke delivery system. A third smoke delivery system (FIG. 5) employed a venturi effect to draw smoke from the fire box into the enclosure. Such a system was inefficient and delivered little smoke to the enclosure. Therefore, even though the Hamilton et al. device provided for separate control of the temperature, pressure, and smoke concentrations within the enclosure, the smoke delivery system was either ineffective at delivering smoke or resulted and failure of the compressor due to smoke contamination.
Thus, there is a need in the art for a smoker that cooks or cures foods at less than atmospheric pressure. Further, there is a need in the art for a device that also smokes foods under pressure with separate controls for temperature, pressure, and smoke concentration within the smoking enclosure and that delivers smoke in a manner that does not destroy device components.